Open AccessCusps in cold dark matter haloes
Author(s) -
Diemand Jürg,
Zemp Marcel,
Moore Ben,
Stadel Joachim,
Carollo Marcella
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09601.x
Subject(s) - physics , astrophysics , virial theorem , halo , cold dark matter , dark matter , radius , cluster (spacecraft) , cuspy halo problem , dark matter halo , galaxy , computer security , computer science , programming language
We resolve the inner region of a massive cluster forming in a cosmological Λ cold dark matter (CDM) simulation with a mass resolution of 2 × 10 6 M ⊙ and before z = 4.4 even 3 × 10 5 M ⊙ . This is a billion times less than the cluster's final virial mass and a substantial increase over current ΛCDM simulations. We achieve this resolution using a new multimass refinement procedure and are now able to probe a dark matter halo density profile down to 0.1 per cent of the virial radius. The inner density profile of this cluster halo is well fitted by a power law ρ∝ r −γ down to the smallest resolved scale. An inner region with roughly constant logarithmic slope is now resolved, which suggests that cuspy profiles describe the inner profile better than recently proposed profiles with a core. The cluster studied here is one out of a sample of six high‐resolution cluster simulations, and its inner slope of about γ= 1.2 lies close to the sample average.